Nibali defends choice to work with dope-tainted Vinokourov

ST ETIENNE France (Reuters) - A Tour de France yellow jersey holder will always be grilled about doping and Vincenzo Nibali was no exception on Thursday, having to defend his choice to work with former doper Alexandre Vinokourov.

Nibali joined Astana last year from Liquigas and fell under the guidance of Kazakh Vinokourov, who served a two-year ban after being found guilty of blood doping on the 2007 Tour de France.

Vinokourov came back to the sport and won the 2012 Olympic title in London before taking over as Astana manager.

Kazakh-funded team Astana have a tainted reputation since their first year in 2007, when Vinokourov was kicked out of the Tour following his doping offense.

It was also the team Spain's Alberto Contador was riding for in 2010 when he tested positive for a banned anabolic agent.

But Nibali believes things have changed as he works with sports director Giuseppe Martinelli - the one who led the disgraced Marco Pantani to his Giro d'Italia title in 1998.

Quizzed about his choice to work with Vinokourov and Martinelli after the 12th stage of the Tour de France on Thursday, Nibali said: "I could not say anything about Martinelli, with whom I have a good relationship.